Linux?

It says in the trailer that this game is available for Linux, but I'm not seeing it here or on Steam as an option, and I don't see an option to buy it directly from the website either. Am I missing something obvious?

The trailer is really old (2013), Linux support ended in 2014/5 because of the immense difficulty of getting it to work with Adobe Air on many platforms. Steam does not list Linux but if you buy there an old version will download that contains a standalone SWF file (no achievements) that can be played.